Chemical feeders



y 8, 1968 M. E. GILWQOD 3,385,483

CHEMICAL FEEDERS Original Filed March 27, 1964 llllllllllll' INVEN TOR.

United States Patent 3,385,483 CHEMICAL FEEDERS Martin E. Gilwood, 33 Braeburn Drive,

Princeton, NJ. 08540 Continuation of application Ser. No. 355,309, Mar. 27, 1964. This application July 21, 1966, Ser. No. 573,436 Claims. (Cl. 222--416) ABSTRACT OF THE DISCLOSURE This invention relates to chemical feeders and the method of feeding chemicals which provide controlled dissolution of briquetted chemicals in a liquid solvent. The briquetted chemicals are mounted vertically on a support platform in a dissolving chamber. The support platform is located at an elevation below an overflow outlet in the dissolving chamber. A regulated flow of sol vent is supplied continuously to a measuring chamber which is provided with a siphon conduit leading to the dissolving chamber. The solvent contents of the measuring chamber are periodically dicharged through the siphon conduit periodically raising the solvent level in the dissolving chamber suficiently to contact the supported briquetted chemicals and dissolving a portion of the briquetted chemicals. The period of contact of solvent with chemicals is controlled by adjusting the rate of draining solvent through a secondary outlet from the dissolving chamber, located below the briquette support platform.

This invention relates to chemical feeders with controlled dissolution of agglomerated or briquetted chemicals. This application is a continuation of applicants copending patent application Ser. No. 355,309 now abandoned.

It is an object of this invention to provide a chemical feeder suitable for dissolving agglomerated or briquetted soluble chemicals in proportion to the flow of solvent through the feeder. Such feeders are of special value for feeding small amounts of chemicals to liquids at atmospheric pressure located at a level below the level of the feeder. For example, such chemical feeders are of special value for feeding continuously small amounts of chemicals to water cooling towers to prevent corrosion and scale in the cooling system.

Another object of the invention is to provide a means for easily controlling the amount and rate of chemicals dissolved in solution in the feeder.

These and other objects of the invention will become apparent upon consideration of the detailed description and the claims which follow.

In the feeder referred to herein, the agglomerated or br quetted soluble chemicals are stored in a vertical supply container or preferably a tube of substantially uniform cross-section and the bottom layer of the stored chemical column is periodically contacted with solvent or dissolving solution.

FIG. 1 is a vertical cross-sectional view of an apparatus according to the invention showing the relationship of the various components. It should be understood that the invention is not limited to the specific structural details of the embodiment shown.

The feeder comprises an inlet measuring chamber 3 into which solvent for the agglomerated chemical enters through inlet conduit 2 at a rate controlled by valve 1. When the level of solvent rises sufiiciently in measuring chamber 3 to start siphoning through conduit 4 the contents of measuring chamber 3 are discharged through drain conduit 8 into dissolving chamber 9. The size of conduit 4 and drain conduit 8 must be such that the rate of discharge flow during siphoning is substantially 3,385,483 Patented May 28, 1968 greater than the rate of inlet flow of solvent through valve 1 into measuring chamber 3. Thus, once siphoning starts the liquid level in measuring chamber 3 will continue to rapidly drop until the level reaches siphon conduit suction inlet '5. Air will then be sucked into the siphon, breaking the siphon flow, thus interrupting the discharge into dissolving chamber 9. A substantially constant volume of solvent will thus be discharged periodically from measuring chamber 3 into dissolving chamber 9.

The volumetric content of measuring chamber 3 and dissolving chamber 9 must be so proportioned that the volume of solvent discharged from measuring chamber 3 into dissolving chamber 9 is 'more than suflicient to overflow from chamber 9, through overflow conduit 14 and be discharged through conduit 17 to the location to which it is desired to feed the chemical. The solvent level remains constant at the height of the overflow until the siphoned discharge entering chamber 9 from chamber 3 is terminated by the breaking of the siphon. The level in chamber 9 then drops as solvent is discharged through orifice 16. Orifice 16 is of such size as to be capable to drain a substantial volume of solvent contained in chamber 9, from the level of the overflow, before the next periodic discharge of siphoned solvent enters chamber 9 from measuring chamber 3. The solvent level in dissolving chamber 9 will rise and fall in a periodic cycl The agglomerated or briquetted chemical 15 stored in vertical columnar chamber 7 is mounted vertically above support platform 12. Platform 12 is preferably constructed of porous, perforated or screened material. The bottom layer of chemical 15 in chamber 7 rests on support platform 12. The elevation of support platform 12 is maintained at a selected level below the overflow level and above the level of orifice 16 to provide the desired immersion depth for contact of solvent with chemical.

Chamber or columnar container 7 should be sufficiently large in cross-section for sliding clearance between the agglomerated or briquetted soluble chemical 15 and the wall of columnar container 7 to avoid jamming therein. It is desirable, but not essential, that the chemical be briquetted with uniform cross-sectional dimensions preferably in the form of flat-ended tablets. As the bottom chemical briquet resting on the support plate dissolves, the agglomerated or briquetted chemical above it drops by gravity until it reaches the support platform. Each briquet reaches the platform successively when the briquet below it has dissolved in the solvent.

Support platform 12 may be mounted on a simple screw-threaded rod 13 which rises from the bottom of chamber 9 and can be readily adjusted to lower or higher elevation by turning. Alternately the support plate .may be supported by adjustable U-bolts or similar fastenings, from the top or side walls of dissolving chamber 9 or from the walls of container 7. It is best to keep the support platform away from the walls of the disolving chamber to keep the briquetted chemicals from jamming the storage column, in the event that any solvent rises up the column of agglomerated chemical by capillarity.

If located outdoors, the top of chamber 7 is preferably provided with a cover 6 to keep out rain water. Similarly,

inlet flow rate through valve 1 into measuring chamber 3 in order to maintain optimum siphon operation.

The chemical feed rate can be further controlled by adjusting the contact time between the agglomerated chemical and solvent. It is another feature of this invention to provide means to control the time of contact 'between chemical and solvent for any given depth of immersion of agglomerated chemical in dissolving chamber 9. For this a means for controlling the discharge rate of solvent from dissolving chamber 9 is provided. For this purpose orifice 16, located below the overflow level, is provided with a suitable adjustable restriction. A simple screw-threaded needle throttle 19 or an adjustable slide gate are sufficient to vary the open area of the orifice. By varying the rate of liquid discharge from this orifice located near the bottom of chamber 9, it is feasible to control the contact time between chemical and solvent from a matter of a few seconds per siphon discharge cycle up to continuous contact throughout the siphon discharge cycle. Thus, the percentage of time of contact between solvent and agglomerated chemical can be varied accurately over a broad range. By adjusting the contact time and the depth of immersion, the rate of dissolution of briquetted chemical and thus the chemical feed rate can be controlled.

It is preferable, but not essential, that the feeder or at least dissolving chamber 9 be made of transparent corrosion-resistant structural material such as glass or clear plastic so that the chemical level, rate of solvent flow into the measuring chamber, siphon discharge cycle time, platform level and contact time of solvent with agglomerated chemical can all be easily observed and adjusted.

I claim:

1. A chemical feeder comprising in combination a vertical chamber for storing agglomerated soluble chemical, said chamber open at its bottom and vertically mounted over a support platform in a dissolving chamber, said platform providing the vertical support for the agglomerated chemical in the dissolving chamber; said platform located at an elevation below an overflow level outlet from said dissolving chamber; a secondary smaller outlet from said dissolving chamber located at an elevation below said support platform; a measuring chamber located above the dissolving chamber, said measuring chamber having a solvent inlet conduit, a flow regulating valve in said conduit and a siphon conduit for leading solvent from said measuring chamber into cyclic contact with the bottom portion of agglomerated chemical resting on support platform in said dissolving chamber to dissolve said portion of agglomerated chemical.

2. A chemical feeder as in claim 1 including means for throttling the flow through said secondary outlet.

3. A chemical feeder as in claim 1 including means for changing the relative elevation of said support platform and said overflow level outlet.

4. A chemical feeder as in claim 2 including means for changing the elevation of support platform.

5. A chemical feeder as in claim 1 wherein said siphon conduit provides a higher flow rate than the inlet conduit flow rate and provides a substantially greater solvent inlet flow rate to said dissolving chamber than the solvent discharge rate through the secondary outlet in said dissolving chamber so as to provide a cyclical variation in solvent level from the overflow level to a level below the support platform.

6. A chemical feeder for dispensing soluble agglomerated chemicals in liquid solvent, comprising a vertical chamber for storing said chemicals, said chamber open at its bottom and vertically mounted over a support platform located at an elevation below an overflow level outlet from the dissolving chamber, said platform providing the vertical support for the agglomerated chemical in the dissolving chamber, a secondary throttled smaller outlet from the dissolving chamber located at an elevation below the support platform; a measuring chamber located above the dissolving chamber; said measuring chamber having a solvent inlet conduit, a fiow regulating valve inlet conduit; a siphon conduit leading from said measuring chamber into said dissolving chamber; solvent being continuously introduced into said measuring chamber through said inlet conduit while said feeder is .in operation, raising the level therein above the top of the siphon conduit downcomer to initiate siphoning action; said siphon periodically rapidly discharging said liquid solvent from measuring chamber into dissolving chamber; thereby raising liquid solvent level in said dissolving chamber above the support platform and dissolving agglomerated chemical thereon; said liquid solvent level in dissolving chamber being lowered below support platform after each siphonic solvent discharge from said measuring chamber, by discharging through said secondary outlet from dissolving chamber.

7. A chemical feeder as in claim 6 provided with means for changing the relative elevation of said support platform and said overflow level outlet.

8. A chemical feeder as in claim 6 provided with means for throttling the flow through the secondary outlet.

9. The process of feeding briquetted soluble chemicals into a liquid solvent which comprises mounting the briquatted chemicals vertically on a support platform located at an elevation below an overflow outlet in a dissolving chamber; supplying a continuous flow of solvent at constant rate to a measuring chamber located above said dissolving chamber, said measuring chamber having a siphon conduit leading from said measuring chamber to said dissolving chamber; said continuous flow of solvent raising the solvent level in said measuring chamber above top of said siphon conduit to initiate siphoning action and periodically rapidly emptying liquid solvent from said measuring chamber into said dissolving chamber, thereby raising the liquid level in said dissolving chamber to overflow through said overflow outlet, thereby periodically contacting briquetted chemicals on said support platform, dissolving a portion of briquetted chemical thereon; periodically lowering the solvent level in said dissolving chamber to discontinue solvent immersion of the briquetted chemicals, by draining solvent from the dissolving chamber through a secondary outlet located below the briquette support platform, at a regulated rate of flow.

10. The method of feeding briquetted soluble chemicals into a liquid solvent as in claim 9 wherein the chemical feed rate is adjustably controlled by varying the solvent draining rate through the secondary outlet from said dissolving chamber.

References Cited UNITED STATES PATENTS 1,293,017 2/1919 Broche 2224l6 3,094,134 6/1963 Currie 23-267 X 3,107,156 10/1963 Fredericks 23-267 ROBERT B. REEVES, Primary Examiner.

N. L. STACK, Assistant Examiner. 

